1. Field of the Invention
The invention relates to an ion permeable membrane made by a method. More particularly, the invention relates to an electrochemical cell including the ion permeable membrane.
2. Discussion of the Related Art
Polymeric, non-porous, membranes are typically thin films comprising amorphous phases of structural molecules comprising long chain polymers. These membranes are impermeable to liquids and vapors. Polymeric membranes can be made to have permeability to specific groups of ions such as anions or cations. In general, the selectivity of an ion permeable membrane is based on specific physical limitations imparted to the membrane by its structure. Certain long chain polymers having the ability to transport ions along their length are referred to in the art as pores. Selectivity may result from the long polymer chains containing isolated charges along the length of the chain. These charges may be provided by ion exchange monomers. In polymers including these monomers, the active charge ion exchange radicals are distanced from each other resulting in isolated charges along the chain. The distance between the charge sites allows transport of only selected ions along the polymer chain.
Lithium ion cells are known for a high energy density. However, their manufacturing cost is relatively high due to special fabrication requirements. In addition, the presence of reactive lithium and flammable electrolyte can be dangerous in some environments where the cells might be used.
There remains a need in the art for an improved ion permeable membrane for a electrochemical cell. Problems found in the prior art are solved, at least in part, by the method for an electrochemical cell with the ion permeable membrane of the invention.